Yamaha YZF-R125 Owners Manual: Motorcycle care and storage

Troubleshooting charts

Starting problems or poor engine performance Starting problems or poor engine performance Engine overheating WARNING Do not remove the radiator cap when the engine and radiator are hot. S ...

Matte color caution

NOTICE Some models are equipped with matte colored finished parts. Be sure to consult a Yamaha dealer for advice on what products to use before cleaning the vehicle. Using a brush, harsh ch ...

Other materials:

Removing the valves
The following procedure applies to all of the valves and related components. NOTE: Before removing the internal parts of the cylinder head (e.g., valves, valve springs, valve seats), make sure the valves properly seal. 1. Check: Valve sealing Leakage at the valve seat Check the valve ...

Ecu self-diagnostic function
The ECU is equipped with a self-diagnostic function in order to ensure that the fuel injection system is operating normally. If this function detects a malfunction in the system, it immediately operates the engine under substitute characteristics and illuminates the engine trouble warning li ...

Faulty clutch
Clutch slips 1. Clutch Improperly assembled clutch Improperly adjusted clutch cable Loose or fatigued clutch spring Worn friction plate Worn clutch plate 2. Engine oil Incorrect oil level Incorrect oil viscosity (low) Deteriorated oil Clutch drags 1. Clutch Unevenly t ...